Rankin is a borough in Allegheny County, Pennsylvania, United States, 8 miles (13 km) south of Pittsburgh on the Monongahela River. The borough was named after Thomas Rankin, a local landowner. Early in the 20th century, Rankin specialized in manufacturing steel and wire goods. The population increased from 3,775 in 1900 to 7,470 in 1940, and has since declined to 2,122 as of the 2010 census.
Rankin is located at 40°24′40″N 79°52′44″W (40.411069, -79.878884).
According to the United States Census Bureau, the borough has a total area of 0.5 square miles (1.3 km2), of which 0.4 square miles (1.0 km2) is land and 0.1 square miles (0.26 km2), or 12.00%, is water.
Rankin has three land borders, including Swissvale to the north and west, and North Braddock and Braddock to the east. Across the Monongahela River to the southwest, Rankin runs adjacent with Munhall and Whitaker, the latter with a direct connector via Rankin Bridge.
As of the census of 2000, there were 2,315 people, 1,002 households, and 603 families residing in the borough. The population density was 5,299.5 people per square mile (2,031.4/km2). There were 1,126 housing units at an average density of 2,577.6 per square mile (988.1/km2). The racial makeup of the borough was 27.99% White, 69.33% African American, 0.13% Native American, 0.17% Asian, 0.39% from other races, and 1.99% from two or more races.